Part of it is definitely down to having the Moleskine, and carrying it with me everywhere - being able to scribble down ideas, snippets whenever I can is really helping. I'm also sure that the quality of said little notebook helps - it's nice having something that looks and feels good to work in. And telynor is dead right about a fountain pen too. :) Having picked up a black Lamy Safari at Rymans yesterday, I've discovered two things:

it makes me write slower and neater, because

writing becomes a joy, above and beyond just a means of getting words down on paper. I find myself writing things down more!

I haven't owned a fountain pen since senior school (barring a few calligraphy pens at university), and I'd forgotten how tactile and pleasant the act of laying ink down on paper with a nib is compared to using a biro or even a gel or fibre tip.